The lifting of 44 gallon or 200 litre drums and other objects having a peripheral rim used to lift the object, presents a problem for farmers, truck drivers and shipping companies who have to invest in expensive and specialised lifting equipment.
Prior art devices currently available for such applications are not only expensive but are adapted to be used with specially designed lifting equipment which is generally not portable. There are however portable and inexpensive devices but these have inherent safety problems such as they are not self-centering or self-locking with respect to the load and are difficult to secure to the load where access space is limited.
Prior art examples of devices especially adapted to lift drums include devices that grasp the side of the drum using flexible straps or rigid bars that are hydraulically or electrically powered and which are only usable with specific types of lifting equipment.
At a general level, the disadvantages of this type of system or apparatus are that they are expensive, not portable, usually require hydraulic or electric power or utilise a manual lever action to apply the grasping force and as a result are not easy to be quickly or efficiently deployed or released.
The hydraulic or electric models are also not able to be adapted for use with all types of lifting devices and are not able to be used where access to the drum is restricted or when the drum is lying on its side.
Another example of the prior art includes a clamp that grasps a drum at two opposed positions near the top of the drum with a scissor or lever action that applies pressure to the sides of the drum. The disadvantage of this example is that it may not distribute weight evenly on the drum as the drum is being lifted and can result in the drum being distorted and/or damaged. The device is also not self-centering and if not properly centred, there is a danger that the drum could slip from the clamp and fall from the height to which it was lifted.
In addition, the hinges on the lever or scissor actioned apparatus could injure the hands of the worker if they become caught. The hinges also present a structural weakness that increases the risk of the drum falling and which requires regular maintenance.
A further example of the prior art includes devices which comprise a set of three (3) dangling rigid bars with hooked ends. This type of device is not self-locking and is not able to be used where the drum is lying on its side or even if the drum is leaning. If the drum or lifting device suffers any jolting action while the drum is being lifted, there is a great chance that the drum will fall from the device.
As a final example, there are devices which comprise pre-welded lugs or bars on the drum for use with a forklift or via chains attached to the lugs. This method of grasping drums means that only those drums with pre-welded lugs may be lifted. This forms a large commercial disadvantage as any other type of drum would not be able to be lifted using this method.